In a nutshell I have a Howa 1500: I've reloaded .223 magtech once-fired brass which was originally off-the-shelf magtech 55gr FMJ (which chambered smoothly in my Howa without problem). I took 30 of these once-fired cases. I prepped the brass by depriming, ultrasonic cleaning and neck resizing with the lee loader. The length of the brass (only full case) was checked against the factory with calipers, the sierra manual and saami. Then on to priming (flush), charging and seating a 53gr sierra matching HP with flat base, matching the overall length of the factory magetch ammo.
I would not suggest simply copying the COAL of the Magtech factory ammo loaded with an FMJ. You are using a different bullet. I would instead suggest that you seat the Sierra Match King to a COAL recommended in reputable reload data for that specific model. Since you have a Sierra manual I would look to that for load data for that specific bullet and use the COAL which they state. Generally this will give you a suitable "jump to the lands" to use as a starting point.
Copying a factory round is often a good starting point, but only as long as you are using the same, or a very similarly profiled, bullet.
At the range, about 30% of these reloads had stiff bolt opening and/or closing (none that were fine closing the bolt had issues opening & extracting, if that makes sense). By stiff, the bolt went down a small fraction and then I needed to give it a way more force forward to close it. Similar to opening - something I've not experienced before and I don't think acceptable (even grazed my thumb on the scope rings trying to open the bolt a few times).
I don't think you should have even attempted to shoot the ones where you had difficulty closing the bolt on them. That should have immediately told you to stop, unload them, and set them aside as suspect. Given that you did, then struggled to open the bolt afterwards, you should have stopped immediately, not carried on regardless and discovered that 30% of them were obviously not right.
(but I'm unable to measure shoulders and necks consistenly with just a caliper (right?).
You can measure neck diameter well enough with just callipers, though a micrometer is better. It is quite a useful measurement to do, particularly with this type of sizing. Measure outer diameter of sized neck before seating bullet. Seat bullet. Measure again. It will be larger. The difference is the "neck tension" 2-3 thousands of an inch is OK. Much more than that and you are essentially using the bullet as a neck expander. Not good for the bullet, and maybe undue force down on the shoulder, particularly if trying to force in a flat based bullet, as you are using. Easily detectable if seating on a press, once you have a feel for what's right, but of course with the Lee Loader you don't have any of that, just whack them in with the hammer.
There is every chance of this happening with a Lee Loader, (or even insufficient neck tension, say anything below 1/1000" If so, try the simple bullet push test). it is a one-size-fits all compromise device, The results it gives are largely determined by the neck thickness of your particular brass. Unlike a bushing die, where you select a specific bushing diameter to suit the brass that you are using.
To measure shoulder position you need a comparator. But realise that a comparator only gives a comparison measurement, not an absolute one, used to compare with a fireformed (in your rifle) case. So keep a few of these as reference pieces, maybe three or so.
I consider a body/headspace comparator to be an essential tool for reloaders, unless they are content to just set up their sizing dies in the simplest way, assuming that they will produce brass somewhere inside the SAAMI tolerance band, rather than best fit in a particular rifle. Which is quite an assumption to make.
- My rifle chamber is dirty and needs a good clean. Honestly, I've just been running VFG felts and nylon brushes down the bore and giving the action area a bush and a wipe, not realizing the chamber gets dirty. A flashlight down there shows some waxy like deposits where the shoulder of the round sits. But I look back at all the factory ammo that is chambered without issue. Is it really the chamber? [I plan to do this]
I suggest you buck up your ideas about cleaning. Aren't you using any solvents ? Surely you knew that the chamber needs cleaning as well ? The fact that factory ammo chambered OK in a dirty chamber is unsurprising, it is made to SAAMI tolerances which mean that even the longest (shoulder, i.e headspace) cartridge will fit the shortest chamber. Or the other way around there can be (typically) up to 0.010" of headspace allowed, which is far too much for best accuracy, but deemed safe, and should fit any correctly chambered rifle.
BTW, keep your bolt lugs and the receiver recesses clean and greased too.
Once you have shot the factory ammo it will have fireformed to your chamber, so become a snug fit. if not an almost interference fit. This rather depends on the stiffness of your action, as it fireforms under the peak pressure, when the bolt thrust is at its highest, which is not the situation when you rechamber a fireformed case that has only been neck sized. It usually works because the brass springs back a little after the first fireforming, but less and less so on subsequent firings, where it is starting off much more closely conforming to the chamber.
Usually you can get away with only neck sizing for several reloadings, particularly if you only use mild to moderate loads.
My only experience with a Lee Loader was when I got my first centrefire, a Lee Enfield No.4 in 303. The club reloading guru kindly lent me a Lee Loader, which worked nicely for cast lead bullets downloaded for the indoor 25 yard range. reloaded cases many times over with never a problem. But as soon as I tried using it for proper loads with FMJs on the outdoor ranges it failed. Neck sizing only worked maybe once, or twice, before the bolt became stiff to close. The Enfield action is not particularly stiff, the bolt lugs are at the rear, and the receiver flexes a little when under the force during firing. So the cases fireformed slightly longer than the chamber actually was.
Which is why I then bought a Lee hand press, and a set of three dies, full length, Lee collet neck, and seater. Learned how to set the FL die for minimal shoulder bump for the full power loads, and used the neck die only for the downloads.
No further interest in the Lee Loader after that.
Your Howa action should be far stiffer, but nevertheless, if you are using anything more than mild to moderate loads, expect to have to bump the shoulder back a little at some point.
Simple test, after you have shot a round, re chamber the empty case in your rifle. If it is already beginning to show any signs of stiffness in closing the bolt, then it's pointless simply trying to neck size it again. Time to either bin it, or FL size it.
- If I were to reload the same way again but try to chamber each round directly after cleaning (unprimed/charged/bullet-seating), that would be able to identify the outliers. Could I then colour in the ill-fitting cases with a permanent marker and then see where the issue is after chambering>extracting? This is diagnosis, but not fix! [I plan to do this, unless feedback suggests not to]
Yes of course you should test fit each resized case (but otherwise empty of primer, powder and bullet) in your rifle until you are confident of your technique.
- Neck sizing is insufficient and I should FL resize. I don't want to believe this! Perhaps my chamber is close to the margin and not liking the rounds the loader is delivering? Is the "hammering" of the bullet seater changing the shoulder or neck that much?
Neck sizing could work for several, if not many, reloads. Particularly if you only use moderate loads, though you might find that limiting as you progress. But sooner or later the shoulder will need to be bumped back, unless the brass has otherwise become worn out before then.
